/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/SelectiveTessellate.h
The caller is responsible for managing the memmory the pointers are pointing to. The operator simply populates the data structures if they are not null.
struct FTessellationInformation
TArray< int32 >...
SelectedVertices
If not null, construction of tessellated mesh will append a list of all the vertices that belong to triangles affected by the tessellation.